During high vertical acceleration events, such as a rotorcraft crash or ground vehicle mine blast event, the spine of an occupant can fracture due to compressive loading. To limit spinal loading, energy absorbing (or load limiting) seats have sometimes been utilized in aviation and ground vehicles. Any additional weight borne by the upper torso of an occupant of an aviation or ground vehicle, such as a helmet, armored vest, survival gear, etc., generally adds to the compressive loading of the spine during a crash or blast event, thereby increasing the risk of injury. To counter the effects of added upper torso weight, some seat energy absorbers could be set at a lower stroking load. However, such a modification also requires more seat stroke, space for which is not available in many existing aviation and ground vehicles.
Excessive weight mounted to the upper torso of an occupant also increases muscle fatigue for rotorcraft pilots who often operate in the helo-hunch position. The poor posture of the occupant combined with vibratory exposure can lead to chronic back injury/pain during extended missions which can affect mission capability and readiness.
One prior disclosure, in U.S. Pat. No. 9,370,237, describes an active spinal support system that utilizes a multi-segmented spinal column with tension tendons actuated by electrical motors. The active spinal support system arrangement, however, is complex, heavy, and costly. In addition, the active spinal support system disclosed does not provide precise positioning of the occupant torso position and is only effective in certain crash situations.
Accordingly, there is a desire for improved vehicle seating support systems that will provide enhanced seating of increased safety which will provide an effective resistive force to occupant motion and reduce compressive loading on the spine of an occupant in the event of a crash or blast to a vehicle.